New Start Battery

[britinusa]

Hi Guys, time to replace the Start Battery ( 5 years old and getting cranky )

I'm in the process of installing a Victron BtoB battery charger to my system ( just finished replacing the entire electrical power management system ). The B2B will charge the Start battery from the House Battery ( currently a 2S2P Trojan T105 6v Battery bank but getting replaced with a LiFePo4 battery bank by the end of the $year.

The current Duracell 12v AGM battery has the terminals on the side and it's mounted under the hanging locker aft of the Nav Table.

Not sure if our current battery is the most appropriate, but definitely want an AGM.

Can you suggest the most appropriate ratings for the battery and any recommendations for the battery brands.

Thanks

Paul

[waughoo]

I installed a group 78 side post from Interstate that is AGM.  This is installed under the aft berth which was my reason for a side post battery.  If memory serves correctly, it has 750 to 800CCA which is well above what the universal really needs.  Additionally, most boats aren't operating at below freezing temps and thus the marine cranking amps are more relevent.  This battery has somewhere round a 900 to 1000 MCA rating.  It has proven to be a great addition to my boat and starts the m35 swiftly.

[britinusa]

The side mounted terminals option is the same for Eximius, I'm pretty sure there's not enough space above the battery for top mounted terminals. The AGM requirement is simply because that's what we have and it has worked great.
Got a link to that interstate?

Paul

[mark_53]

The side mounted terminals option is the same for Eximius, I'm pretty sure there's not enough space above the battery for top mounted terminals. The AGM requirement is simply because that's what we have and it has worked great.
Got a link to that interstate?

Paul

An AGM that lasted only 5 years?  Doesn't sound so great to me.  My Walmart flooded group 78 lasted that long.

[Noah]

I believe flooded MAY last longer. You might consider a sealed "maintenance-free" group 24 flooded type. I don't know about whether they make one with side terminals. Mine has top terminals and fits in a plastic battery box under the aft bunk. It is strapped down but does not have clearance to include the battery box's top. However, it does not need the top, as it is strapped down and the bunk board acts as a top.

[britinusa]

The current battery is only charged when shore power is onboard and we don't leave shore power connected unless we're working on the boat, and then the charging status was only via a Xantrex trickle charger and, unbeknown to us, that was not working consistently. When we realized the failure of the charging and trickle charging system, I changed out the Xantrex with a complete Victron System.

The alternator is not connected to the Start Battery.

Also, we're in South Florida, the conditions down here are fatal to batteries and not having a reliable charging system only reduces their lifetime.

As mentioned, I'm going to install a B2B charger for the Start Battery.

[waughoo]

Brit:

I have the victron b2b from the house bank and then the alt set to charge the house bank.  The 110 charger also only charges the house bank.  Thus, with the V B2B, the start battery gets charged regardless of what's happening.  As soon as there is charge current detected, the V B2B starts doing its thing.

Paul,

I don't have a link for you.  I would have to look it up in my notes to see the ACTUAL model number.

[britinusa]

That sounds like the exact system I'm setting up for the Start Battery.  The Victron Orion Smart TR 12/12 18Amp B2B charger is on it's way. ( From eMarine in Fort Lauderdale but they're waiting for delivery )

BTW, my system is on Victron World, I'm in South Florida. I think there are only 2 of us, me and Vitality.  https://vrm.victronenergy.com/world/# no password required.

If it arrives early enough, the B2B will be installed before we head out for a 4 day cruise up the ICW next Friday. ( with the new battery )

Paul

[britinusa]

Alex, do you have Solar too?
Currently I have 1x170W, 2x65w and Victron 100/20 MPPT and that also charges the House Bank. ( Upgrading to 510w in the Spring )

I'm guessing that if the house bank V is high enough due to Solar Charging then the B2B will kick in also. Of course, if the Start battery is fully charged it won't be an issue.

Paul

[waughoo]

I don't have solar yet.  Next piece of "blue candy" for me is the multi-plus.  The nice thing about the b2b charger is it just does its thing when you have charging voltage.  It is VERY low drama.